1. Field of the Invention
This invention relates to handles for surgical instruments, including heart surgery instruments. In particular, this invention relates to an improved handle for hand held surgical instruments of the type having a tool with at least one articulated member thereon wherein the handle has a means for actuating the articulated member and selectively locking or disengaging from locking the articulated member intermittently in an open or closed position. This invention also encompass a handle which allows rotation of the tool to a desired radial position.
2. Background Art
Surgery is a learned art requiting many hours of advanced training and skills development that extends far beyond a thorough understanding of the medical principles involved, e.g., anatomy, physiology, principles of wound healing, and the like. The surgeon must also develop hand-to-eye coordination and acquire skills in the art of atraumatic tissue manipulation utilizing a variety of highly specialized surgical instruments.
The surgical instrument actually becomes an extension of the surgeon's hand. The surgeon must develop an ability to feel and respond, often delicately yet firmly, through his surgical instruments. Accordingly, there exists a need for instrument handles which are sensitive, responsive and ergonomically designed to augment the natural motions of the human hand.
The actuating mechanism for handles of currently available surgical instruments are usually configured such that the pivot point is located between the handle lever and the articulated member (a forwardly located pivot point). The handle can have either one or two lever arms which are moveable about the pivot point. Such configuration is opposite to the natural pivot points of the hand.
One example of prior art handles of the type described above is the conventional "scissors" type handle with a forward pivot point, e.g., Mayo or Metzenbaum scissors, or Debakey forceps. The scissors handle design usually lacks a means for biasing the instrument tool in an open position. Of necessity, therefore, these scissors type handles have finger and thumb rings located at the free ends of the lever arms which provide a means for receiving force and balancing the instrument when both opening and closing the lever arms of the handle.
The scissors type handles are usually held by inserting the thumb through the thumb ring, balancing the scissors against the index finger and inserting one or more of the remaining digits into the finger ring of the opposite lever. Movement of the lever arms is accomplished by apposing the thumb and digits which are in the finger ring. This design requires increased muscular effort to open and close the levers and, therefore, fatigues the hand of the surgeon.
A second example of the forward pivot point configuration is the "pliers" type handle which is functionally similar to the scissors handle but without finger rings. In this configuration, movement of the levers from the open to the closed position is accomplished by closing the palm of the hand in a squeezing motion. A bow spring or other spring configuration located between the lever arm is sometimes included as a means to bias the handle in an open position to compensate for the lack of finger rings.
Neither the scissors nor the pliers type of handles are capable of being held and moved by the tips of the fingers, which results in a significant loss in sensitivity.
A third type of handle utilizes an actuator having two bowed springs connecting a rearwardly projecting actuator rod to handle levers which pivot about a forward pivot point. Although this handle may be held in a manner which allows for fingertip control, the forwardly located pivot point, opposite from the natural pivot point of the hand, results in loss of leverage and decreased sensitivity of the instrument. For fingertip control, the surgeon must sacrifice leverage by placing the fingertips away from the lever ends and closer to the forward pivot point.
One type of instrument which utilizes a rearwardly located pivot point is the forcep, e.g., Adison, Potts-Smith, or general tissue forceps. Forceps utilize the thumb and index finger in a "pencil" grip fashion. However, forceps are not designed to activate an articulated member of a tool, e.g., a needle holder, retractor, or hemostat. Rather the distal ends of the forcep lever arms actually comprise the tool itself.
The present invention satisfies the need in the art for a more sensitive and ergonomic handle by providing an instrument handle that is designed to functionally mimic and create functional harmony with the natural gripping mechanism and motion that exists between the thumb and index finger of the human hand.
The invention also provides an actuating means which moves forward to manipulate the tool when the handle level is depressed into the closed position. The invention also provides a biasing means to maintain the handle in the open position. The present invention additionally provides a means for locking the handle in a variety of positions, including the open and the closed positions, or, alternatively, unlocking the locking means to provide free movement of the handle. The invention also provides a means for rotating the surgical tool so that the tool can be disposed at a desired radial orientation. The invention satisfies the need for a surgical handle that is simpler to manufacture, assemble and disassemble than the prior art.